1. Field of the Invention
The present invention relates generally to a method and apparatus for filling containers with a relatively viscous material and, more particularly, to such a method and apparatus for filling generally cylindrical, plastic barbell weight shells with a relatively viscous slurry of a cementitious material.
2. Description of the Prior Art
The use of barbells, which comprise an elongated bar and one or more generally cylindrically shaped weights mounted on each end of the bar, has long been known for exercising and physical fitness purposes. In recent years, a large number of barbell weights generally have been made from hollow plastic shells filled with a solidified cementitious material, as shown in U.S. Pat. No. 3,171,652 to Newman. Various problems are encountered in the manufacture of such barbell weights, principally because of the difficulty of filling the shells uniformly with a slurry of such a material due to the very viscous nature of the slurry.
One prior art apparatus and associated method for filling plastic barbell weight shells are disclosed in U.S. Pat. Nos. 3,270,390 and 3,360,019 to James. These patents teach that a plurality of barbell weight shells are supported on an elongated rod beneath a dispensing hopper having a plurality of downwardly projecting nozzles. Each of the nozzles fits into an opening in one of the shells for dispensing a relatively viscous slurry of a cementitious material from the hopper into the shell. Vibrators are associated with the shell support rod and the dispensing hopper for assisting the flow of material from the hopper into the shells. Although such a system has been successful for filling barbell weight shells, it is not as efficient as might be desired. Only a given number of shells can be filled at one time after which the filled shells must all be manually removed from the shell support bar and a group of empty shells manually inserted thereon. The necessity for such a large number of manual operations results in a relatively slow shell filling rate at a relatively high labor cost.
Various other prior art patents disclose various types of systems for automatically or semiautomatically dispensing various types of material into containers. For example, U.S. Pat. No. 3,149,188 to Schmitt discloses an apparatus for dispensing soap into cylindrical shells, U.S. Pat. No. 1,094,380 to Tait discloses a device for automatically filling milk bottles, and U.S. Pat. No. 766,329 to Cunning discloses a process for automatically filling cans. However, none of the processes and devices disclosed in these prior art patents is well adapted for efficiently filling containers with a relatively viscous material.